The Peculiar Radio Evolution of the Tidal Disruption Event ASASSN-19bt
We present detailed radio observations of the tidal disruption event (TDE) ASASSN-19bt/AT 2019ahk, obtained with the Australia Telescope Compact Array, the Atacama Large Millimeter/submillimeter Array, and the MeerKAT radio telescopes, spanning 40-1464 days after the onset of the optical flare. We f...
| Main Authors: | , , , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
| Published: |
2024
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| Online Access: | http://purl.org/au-research/grants/arc/DP200102471 http://hdl.handle.net/20.500.11937/97224 |
| _version_ | 1848766241602273280 |
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| author | Christy, C.T. Alexander, K.D. Margutti, R. Wieringa, M. Cendes, Y. Chornock, R. Laskar, T. Berger, E. Bietenholz, M. Coppejans, D.L. De Colle, F. Eftekhari, T. Holoien, T.W.S. Matsumoto, T. Miller-Jones, James Ramirez-Ruiz, E. Saxton, R. van Velzen, S. |
| author_facet | Christy, C.T. Alexander, K.D. Margutti, R. Wieringa, M. Cendes, Y. Chornock, R. Laskar, T. Berger, E. Bietenholz, M. Coppejans, D.L. De Colle, F. Eftekhari, T. Holoien, T.W.S. Matsumoto, T. Miller-Jones, James Ramirez-Ruiz, E. Saxton, R. van Velzen, S. |
| author_sort | Christy, C.T. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We present detailed radio observations of the tidal disruption event (TDE) ASASSN-19bt/AT 2019ahk, obtained with the Australia Telescope Compact Array, the Atacama Large Millimeter/submillimeter Array, and the MeerKAT radio telescopes, spanning 40-1464 days after the onset of the optical flare. We find that ASASSN-19bt displays unusual radio evolution compared to other TDEs, as the peak brightness of its radio emission increases rapidly until 457 days post-optical discovery and then plateaus. Using a generalized approach to standard equipartition techniques, we estimate the energy and corresponding physical parameters for two possible emission geometries: a nonrelativistic spherical outflow and a relativistic outflow observed from a range of viewing angles. We find that the nonrelativistic solution implies a continuous energy rise in the outflow from E ∼ 1046 to E ∼ 1049 erg with outflow speed β ≈ 0.05, while the off-axis relativistic jet solution instead suggests E ≈ 1052 erg with Lorentz factor Γ ∼ 10 at late times in the maximally off-axis case. We find that neither model provides a holistic explanation for the origin and evolution of the radio emission, emphasizing the need for more complex models. ASASSN-19bt joins the population of TDEs that display unusual radio emission at late times. Conducting long-term radio observations of these TDEs, especially during the later phases, will be crucial for understanding how these types of radio emission in TDEs are produced. |
| first_indexed | 2025-11-14T11:48:01Z |
| format | Journal Article |
| id | curtin-20.500.11937-97224 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T11:48:01Z |
| publishDate | 2024 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-972242025-04-30T02:08:06Z The Peculiar Radio Evolution of the Tidal Disruption Event ASASSN-19bt Christy, C.T. Alexander, K.D. Margutti, R. Wieringa, M. Cendes, Y. Chornock, R. Laskar, T. Berger, E. Bietenholz, M. Coppejans, D.L. De Colle, F. Eftekhari, T. Holoien, T.W.S. Matsumoto, T. Miller-Jones, James Ramirez-Ruiz, E. Saxton, R. van Velzen, S. We present detailed radio observations of the tidal disruption event (TDE) ASASSN-19bt/AT 2019ahk, obtained with the Australia Telescope Compact Array, the Atacama Large Millimeter/submillimeter Array, and the MeerKAT radio telescopes, spanning 40-1464 days after the onset of the optical flare. We find that ASASSN-19bt displays unusual radio evolution compared to other TDEs, as the peak brightness of its radio emission increases rapidly until 457 days post-optical discovery and then plateaus. Using a generalized approach to standard equipartition techniques, we estimate the energy and corresponding physical parameters for two possible emission geometries: a nonrelativistic spherical outflow and a relativistic outflow observed from a range of viewing angles. We find that the nonrelativistic solution implies a continuous energy rise in the outflow from E ∼ 1046 to E ∼ 1049 erg with outflow speed β ≈ 0.05, while the off-axis relativistic jet solution instead suggests E ≈ 1052 erg with Lorentz factor Γ ∼ 10 at late times in the maximally off-axis case. We find that neither model provides a holistic explanation for the origin and evolution of the radio emission, emphasizing the need for more complex models. ASASSN-19bt joins the population of TDEs that display unusual radio emission at late times. Conducting long-term radio observations of these TDEs, especially during the later phases, will be crucial for understanding how these types of radio emission in TDEs are produced. 2024 Journal Article http://hdl.handle.net/20.500.11937/97224 10.3847/1538-4357/ad675b http://purl.org/au-research/grants/arc/DP200102471 http://creativecommons.org/licenses/by/4.0/ fulltext |
| spellingShingle | Christy, C.T. Alexander, K.D. Margutti, R. Wieringa, M. Cendes, Y. Chornock, R. Laskar, T. Berger, E. Bietenholz, M. Coppejans, D.L. De Colle, F. Eftekhari, T. Holoien, T.W.S. Matsumoto, T. Miller-Jones, James Ramirez-Ruiz, E. Saxton, R. van Velzen, S. The Peculiar Radio Evolution of the Tidal Disruption Event ASASSN-19bt |
| title | The Peculiar Radio Evolution of the Tidal Disruption Event ASASSN-19bt |
| title_full | The Peculiar Radio Evolution of the Tidal Disruption Event ASASSN-19bt |
| title_fullStr | The Peculiar Radio Evolution of the Tidal Disruption Event ASASSN-19bt |
| title_full_unstemmed | The Peculiar Radio Evolution of the Tidal Disruption Event ASASSN-19bt |
| title_short | The Peculiar Radio Evolution of the Tidal Disruption Event ASASSN-19bt |
| title_sort | peculiar radio evolution of the tidal disruption event asassn-19bt |
| url | http://purl.org/au-research/grants/arc/DP200102471 http://hdl.handle.net/20.500.11937/97224 |